Since there was no evidence of any pre-impact failure or malfunction that could have degraded aircraft performance, the analysis focuses on the meteorological conditions, flight preparation, and pilot decision making. The weather forecasts and observations indicate that the weather along the planned route was not favourable for the flight. Low stratus accompanied by precipitation, drizzle and fog, as indicated in the forecasts, were present on the route and in the mountainous area. Even if the pilot did not request a weather briefing from the FSS before the flight and the conditions at the departure aerodrome were favourable for VFR flight, it was clear from his radio messages en route that he was aware of the adverse weather along the planned route. The pilot nevertheless continued the flight, having flown this route many times in the past. Given the weather conditions at the time of the accident, all indications are that the pilot descended the aircraft in mountainous terrain below the safe altitude for instrument flight and the obstruction clearance altitude specified on the VFR navigation chart, in the hope that he could continue the flight. The observed damage to the aircraft indicates that it struck the trees at high speed in a horizontal attitude. It is highly probable that the pilot did not realize his situation when the Cessna struck the mountain. In 1990, a TSB safety study on VFR flight in adverse weather conditions stated that this type of accident represents about 23 per cent of all fatal accidents. The study also indicated that experienced pilots tend to be involved in accidents related to decision making rather than a lack of flying skill.Analysis Since there was no evidence of any pre-impact failure or malfunction that could have degraded aircraft performance, the analysis focuses on the meteorological conditions, flight preparation, and pilot decision making. The weather forecasts and observations indicate that the weather along the planned route was not favourable for the flight. Low stratus accompanied by precipitation, drizzle and fog, as indicated in the forecasts, were present on the route and in the mountainous area. Even if the pilot did not request a weather briefing from the FSS before the flight and the conditions at the departure aerodrome were favourable for VFR flight, it was clear from his radio messages en route that he was aware of the adverse weather along the planned route. The pilot nevertheless continued the flight, having flown this route many times in the past. Given the weather conditions at the time of the accident, all indications are that the pilot descended the aircraft in mountainous terrain below the safe altitude for instrument flight and the obstruction clearance altitude specified on the VFR navigation chart, in the hope that he could continue the flight. The observed damage to the aircraft indicates that it struck the trees at high speed in a horizontal attitude. It is highly probable that the pilot did not realize his situation when the Cessna struck the mountain. In 1990, a TSB safety study on VFR flight in adverse weather conditions stated that this type of accident represents about 23 per cent of all fatal accidents. The study also indicated that experienced pilots tend to be involved in accidents related to decision making rather than a lack of flying skill. The pilot did not ask the FSS for a weather briefing for the flight. The weather conditions on the planned route were unfavourable for VFR flight. The pilot encountered adverse weather conditions en route and continued the flight. The mountain on which the aircraft crashed was obscured by fog all morning. The aircraft showed no evidence of pre-impact failure. The aircraft struck the trees at high speed.Findings The pilot did not ask the FSS for a weather briefing for the flight. The weather conditions on the planned route were unfavourable for VFR flight. The pilot encountered adverse weather conditions en route and continued the flight. The mountain on which the aircraft crashed was obscured by fog all morning. The aircraft showed no evidence of pre-impact failure. The aircraft struck the trees at high speed. The pilot continued visual flight in adverse weather conditions. Contributing to the accident was the fact that he did not request weather information for the planned route prior to departure.Causes and Contributing Factors The pilot continued visual flight in adverse weather conditions. Contributing to the accident was the fact that he did not request weather information for the planned route prior to departure.